The easiest way to settle this argument is to look at Central banks around the world. All of them buy and hold Gold as a Foreign Exchange Reserve - the same way as they hold USD or EURO or AUD as foreign exchange reserve. ========== Not many central banks own any substantial amount of gold, and the central bank of Canada sold all theirs a few years back because after a short deliberation they discovered it cost more to keep than sell.
The only reason the USA own theirs is because it's 'tradition', not because it's worth anything, in the big picture it's worth almost zero in terms of the wider economy.
Gold is not a currency, it's an asset, but not a very good one in the long term as the many charts I've posted here will prove.